The July 22 total solar eclipse, visible from China and India (but not the United States), will be the longest in the 21st century. Teams of scientists from around the world will gather in China to study the corona, the sun's outermost atmosphere, for almost six minutes, unusually long for totality.
Most will be stationed at a 3,000-foot mountain site selected by Prof. Jay Pasachoff, a Caltech and Williams College astronomer and planetary scientist, in Tianhuangping, China, not far from Hangzhou or Shanghai.
The July event will be the 49th solar eclipse that Pasachoff has viewed. A champion of using eclipse observations to study the solar atmosphere, he describes the science of eclipses in the cover story of the international journal Nature (June 11 issue). Pasachoff, who is chair of the International Astronomical Union's Working Group on Solar Eclipses, was invited to write the article as part of Nature's coverage of the International Year of Astronomy.
The article describes the history of eclipse discoveries, such as the element helium and the verification of Einstein's general theory of relativity, as well as current themes in eclipse research.
One recent development in eclipse studies is the new computer capability of bringing out low-contrast features. One such spectacular image, involving processing by Miloslav Druckmüller of the Brno Institute of Technology in the Czech Republic, was selected by Nature for its cover.
The detailed structure of the corona is caused by the sun's magnetic field. Pasachoff's work with Druckmüller and with Vojtech Rusin and Metod Saniga of the solar observatory in Slovakia has led to several joint papers in the Astrophysical Journal on views of the changing corona. The corona changes not only from year to year with the sunspot cycle but also even within minutes, as the scientists saw by comparing their observations from Siberia and Mongolia at the last solar eclipse on Aug. 1, 2008. They plan to extend that work this summer with observations from India, China, and islands in the Pacific.
Pasachoff's team in China includes Bryce Babcock, staff physicist at Williams and several undergraduate students from Williams, where Pasachoff is Field Memorial Professor of Astronomy. He chose the site on a visit over two years ago to southern China together with Naomi Pasachoff, a research associate at Williams, and Beijing scientists Yihua Yan and Jin Zhu.
Pasachoff and his colleagues have been studying, in particular, why the solar corona has a temperature of millions of degrees, much hotter than the sun's surface. They do so by using a special rapid-readout electronic camera and single-color filters chosen to show only coronal gas. They look for oscillations with periods in the range of one second, which would signify certain classes of magnetic waves. The detailed structure of the corona, revealed by imaging in the visible and x-ray regions of the spectrum, and the correspondence of bright coronal regions with sunspot groups, shows that magnetism is the cause of coronal heating and the coronal structure. A competing set of ideas of how the corona is heated to millions of degrees involves ubiquitous nanoflares, that is, relatively tiny solar flares going off all the time.
Studies of eclipses, transits of Mercury and Venus across the face of the sun, and occultations of Pluto and other objects in the outer solar system proceed in tandem. For his eclipse studies, Pasachoff uses a set of electronic cameras provided by NASA's Planetary Sciences Division, primarily for use in studying Pluto and other objects in the outer solar system. His studies of Pluto's atmosphere started with similar cameras that had been provided for eclipse work.
Pasachoff's research this summer, as much of his work in the past, is supported mainly by a grant from the Committee for Research and Exploration of the National Geographic Society.
International Astronomical Union's Working Group on Solar Eclipses: http://www.eclipses.infoWilliams College eclipse expeditions:
SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University
Molecule flash mob
19.01.2017 | Technische Universität Wien
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences